Samuel L. Jackson is set to play the Rev. Dr. Martin Luther King, Jr. in “The Mountaintop,” a fictional account of Dr. King’s last night before he was assassinated. The play, written by Katori Hall, takes place in room 306 of Lorraine Motel in Memphis, and begins with a black chambermaid, Camae (played by Angela Bassett), bringing Dr. King a cup of coffee.

To play the role, which will also be his Broadway debut, Jackson said he listened to Dr. King’s speeches, but more importantly, researched how Dr. King spoke conversationally. “I spent an inordinate amount of time searching for interviews and just conversations that he’d had with people so I could hear what his speaking voice was and not his oratory voice, because I’m in a hotel room, he’s not giving a speech, he’s kind of relaxed,” Jackson said in an interview.

The actor said he wanted to work on a way of speaking for Dr. King with which people weren’t necessarily familiar. “I sort of discovered a speaking pattern that works for me and hopefully the exploration of his fears and his hopes for the country when he’s not giving a speech will come through very well for people when they see the play,” he said.

Bassett’s role is imagined — a woman who challenges Dr. King, whose real identity and purpose that night comes more and more into question over the course of the play. Jackson and Bassett first met when they were in the Negro Ensemble Company in the early ’80s together. “I’ve known her forever,” Jackson said of his co-star. “We go to the same church, we play with our kids. We have an incredible chemistry and it’s wonderful to be able to work with a friend that you can trust.”

“The Mountaintop” is currently in previews and will open on Oct. 13 at the Bernard B. Jacobs Theatre.